#include<iostream>
using namespace std;
int main()
{
	pair<int,double> p1;
	cout<<p1.first<<","<<p1.second<<endl;
	pair<string,int> p2("this",20);
	cout<<p2.first<<","<<p2.second<<endl;
	pair<int,int> p3(pair<char,char>('a','b'));
	cout<<p3.first<<","<<p3.second<<endl;
	pair<int,string> p4 = make_pair(200,"hello");
	cout<<p4.first<<","<<p4.second<<endl;
	return 0;
}